Monochloromonobromo derivatives of indigo and process of making same.



.YUNITED STATE-S- PATENT OFFICE.-

GADIENT ENGI, OF BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM OF SOCIETY OF CHEM- IGAL INDUSTRY IN BASLE, OF BASEL, SWITZERLAND.

'- MONOCHLbROMONOBROMO DERIVATIVES F iim'reo AND PROCESS on MAKING SAME.

To all whom it may concern:

Be it known that I, GADIENT ENGI, chemist and'doctor of philoso hy, a citizen of the Swiss Republic, and resi ent of Basel, Switzerland, have invented new and useful Mo- -nochloromonobromo Derivatives of Indigo and a Process for the Manufacture of the Same, of which the following is a full, clear,

and exact s ecification.

In an app ication for United States Letters Patent executed at the same time as the present one, I have described the manufacture of. mixed triand tetrahalogen derivatives of indigo, consisting in treatingmono- 'ordlhloroderivatives of indigo with the reuired uantity of bromin. I havefurther ound that in an analogous manner mixed dihalogenderivatives of indigo, .that isto say, monochloromonobromoderivatives of lndlgo can'be obtained by brominatmg the ""known monochloroderivatives of indigo, (redigo) with 2 atomic sulting from the reaction of chlorin on inljroportions of bromin in presence of a suitab e indifferent diluent or solvent.

- monochloromonobromoderivatives of indigo for about 2 hours in a reflux apparatus, on

an oil bath, to a-temperature of 226 (1., this being the tem erature of the oil bath. After cooling and tering, thesolid matter is washed with alcohol and dried, there being obtained a good yield of monochlor-monobromindigo in the form of a blue crystalline owder. It dissolves in concentrated sulric acid .to ai yellowish-green solution, which passesin the course of the time to a bluish green. Fuming sulfuric acid dissolves Specification of Letters Patent.

Application filed June 14 1907. Serial No. 378.931.

The manufacture of these new Patented Nov. 26, 1907.

I the. dyestuff with a blue coloration; ,it is nearly insoluble in alcohol and benzene even when hot, sufficiently soluble in hot anilin with greenish-blue coloration and in h t nitrobenzene with. ure blue coloration. By its treatment wit alkaline reducing agents particularly with soda 1 e and sodium hydrosulfite, the dyestuif yields a limpid, clear yellow vat dyeing cotton vivid reddish blue tints of an excellent fastness to washing, .chlorin and light.

What I claim is:

1. The described process for the manufacture of IllOIlO0hlOI'OIIIOIlObIOlIlOdBIlVatiVGS of indigo consisting in treating a monochlorindigo with two atomic roportions of bromin in presence of a suitable indifferent medium;

2. ,The described process for the manufacture of monochloromonobromoderivatives of indigo consisting in treating a monochlorindigo with two atomic proportions ofbromin in presence of nitrobenzene.

3. As new roducts the monochloromonobromoderivativesof indigo constituting, in dr state, blue crystalline powders nearly inso uble in alcoholandbenzene, sufficiently soluble in hot.anilin with a yellowish blue coloration and in hot nitrobenzene with a pure blue coloration, soluble inconcentrated sulfuric acid with a yellowish-green coloration turning to a blueish-green in the course of the time, soluble in fuming sulfuric acid with a blue coloration and yielding by their treatment with reducing agents yellowish vats dyeing cotton vivid reddish blue tints fast to washing, chlorin and light.

In witness whereof I have hereunto signed my name this 4 day of June 1907, in the presence of two subscrlbing witnesses.

GADIENT ENGI. Witnesses l GEO. GIFFoRn, AMAND BITTER. 

